Ink jet printing is a well known process in the art to make multicolor images. It is a non-impact method for recording information in response to an electronic signal, such as that generated by a computer. In this process, ink droplets are emitted from a nozzle and deposited on substrates, mainly paper or polymer films and sheets, to form an ink image. To achieve high quality images in ink jet printing, the substrate is usually coated with at least one layer that rapidly absorbs the ink. For the inks are mainly composed of water and a colorant, such coating formulations are hydrophilic and contain appropriate absorptive materials.
It is also possible to transfer the ink image present on the ink receiving layer of an ink receiving sheet, comprising a temporary support and an ink receiving layer, to a permanent substrate. After peeling of the temporary support, the image is transferred to the permanent substrate.
Alternatively, the imaged ink receptor sheet may first be laminated to a transfer element. Then the temporary support of the ink receptor sheet is removed, the imaged ink receiving layer on the transfer element is then laminated to the desired permanent substrate, and finally the transfer element is removed.
Ink jet printing materials and transfer processes are known from U.S. Pat. No. 5,023,129, U.S. Pat. No. 5,141,797, and U.S. Pat. No. 5,984,467. Ink receptor sheets which provide ink images with improved durability are known from U.S. Pat. No. 5,429,860 and U.S. Pat. No. 5,537,137. These materials contain special compounds in the ink receiving layer which compounds are crosslinked by heat, by actinic radiation, or by chemical treatment after ink jet printing. Another method to provide durable ink jet images is disclosed in U.S. Pat. No. 5,766,398. This method provides images with a protective layer on the ink image by using an ink receptor sheet comprising a temporary support, a polymeric film, and an ink receiving layer. After applying an image by ink jet printing to the ink receiving layer, a substrate comprising an adhesive layer is laminated to the imaged ink receptor sheet, and the temporary support of the ink receptor sheet is removed, whereby the polymeric film is revealed as a protective layer of the ink image.
There are still problems with the ink jet materials and processes of the prior art, such as they often have narrow handling latitude during the required lamination and peeling steps. Either high lamination temperatures and slow lamination speeds are necessary or it is difficult to separate the right layers in the peeling steps to get the desired end result.